In what case is it ever easier to swing something that takes much, much more strength to lift than a normal object?
My opinion on Might modifying (some) attack rolls has slid from "of course not" to "undecided". Here's why:
1) The rules seem at the least vague on the subject, and possibly support the "accurate telephone pole" theory. After all, the rules state:
In combat, Might can help you with particular applications of Fists and Weapons: if physical force is a very significant element at play, Might will modify (page 214) the primary skill.
And it's hard to argue that physical force isn't significant when attacking someone with a telephone pole.
2) Maybe it does make sense that it's easier to hit with unwieldy objects. After all, which is easier to dodge; a police baton or a telephone pole? So maybe it's less a matter of increasing accuracy, and more a matter of decreasing defense options. Remember that modifiers that represent taking advantage of an opponent's weaknesses (tagging an opponent's consequence, for example) grant a bonus to "accuracy".
I think that as long as you DON'T increase the weapon rating of the object as well (which would grant a double bonus), it works. So, for example:
Person A hits you with a pole arm. He gets his normal weapon skill and adds weapon:3.
Person B hits you with a ploe arm, but has Mythic Strength. He gets his normal weapon skill and adds weapon:9 (which includes the +6 stress from Mythic Strength).
Person C hits you with a telephone pole, which
requires Mythic Strength (and which he has). He gets his normal weapon skill modified by +3 per Mythic Strength's
Supreme Strength (or at least this interpretation thereof), and adds weapon:9 to the result (which again includes the +6 stress from Mythic Strength). Note that the telephone pole was statted only as a "pole arm" rated at weapon:3 -- but that also required Mythic Strength to wield, therefore allowing the modification. So it's going to do more stress, but that stress is also going to be harder to dodge.